It is proposed to develop the theory and application of dynamic nuclear Overhauser effects to the study of structures of biomacromolecules, especially proteins, and of complexes of proteins with smaller molecules. The dynamic nuclear Overhauser effect is expected to show selectivity even in high molecular weight compounds, and to enable the identification of nearby amino acid residues, mapping of binding sites and determination of local conformation in biomacromolecules. The method will be applied to the binding of lysine vasopressin and oxytocin to neurophysins I and II, the binding of anti-sickling peptides to hemoglobin S, and the conformations of Troponin C and Brady kinin.